[AD] Linux: Demo not building on current CVS

[Peter Hull <peter.hull90@xxxxxxxxxx>]

The demo doesn't seem to work any more:
$ make
... blah .... blah ...
gcc -s -L/usr/X11R6/lib -Wl,--export-dynamic  -o demo/demo 
obj/unix/demo.o -Llib/unix -lalleg-4.2.0 -lalleg_unsharable -lm
obj/unix/demo.o(.text+0x354): In function `main':
: undefined reference to `pick_animation_type'
obj/unix/demo.o(.text+0x380): In function `main':
: undefined reference to `init_display'
obj/unix/demo.o(.text+0x385): In function `main':
: undefined reference to `generate_explosions'
obj/unix/demo.o(.text+0x3a1): In function `main':
: undefined reference to `play_game'
obj/unix/demo.o(.text+0x3a6): In function `main':
: undefined reference to `title_screen'
obj/unix/demo.o(.text+0x3af): In function `main':
: undefined reference to `destroy_display'
obj/unix/demo.o(.text+0x3b4): In function `main':
: undefined reference to `destroy_explosions'
obj/unix/demo.o(.text+0x3d3): In function `main':
: undefined reference to `end_title'
collect2: ld returned 1 exit status
make: *** [demo/demo] Error 1

Pete